Effective valorization of barley bran for simultaneous cellulase and β-amylase production by Paenibacillus chitinolyticus CKS1: Statistical optimization and enzymes application

The agricultural raw industry generates large amounts of annually by- -products that create disposal problems. Hitherto, there have been no reported papers about the simultaneous production of cellulase and β-amylase from these raw materials using Paenibacillus sp. that would reduce the costs. Thus, in this paper simultaneous cellulase (CMC-ase and avicelase) and β-amylase production using barley bran and the application of the natural isolate Paenibacillus chitinolyticus CKS1 and potential enzymes in the hydrolysis process was studied. Response surface methodology was used to obtain the maximum enzyme activity (CMC-ase 0.405 U mL-1, avicelase 0.433 U mL-1 and β-amylase 1.594U mL-1). Scanning electron microscopy showed degradation of the lignocellulosic–starch structure of barley bran after fermentation. The CKS1 bacterial supernatant, which contains cellulases and β-amylase, could hydrolyze cotton fibres and barley bran, respectively. The main products after enzymatic hydrolysis of cotton fibres and barley bran, glucose (0.117 g gmat -1) and maltose (0.347 g gmat -1), were quantified by high performance liquid chromatography (HPLC). The produced enzymes could be used for hydrolysis of cotton fabric and barley bran to glucose and maltose, respectively. Application of simultaneous enzymes production using an agricultural by-product is economically and environmentally accepted and moreover, valuable biotechnological products, such as glucose and maltose, were obtained in this investigation. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 31035 and Grant no. III 45020